poco/XML/include/Poco/XML/XMLWriter.h
2022-07-07 04:18:20 -05:00

376 lines
14 KiB
C++

//
// XMLWriter.h
//
// Library: XML
// Package: XML
// Module: XMLWriter
//
// Definition of the XMLWriter class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef XML_XMLWriter_INCLUDED
#define XML_XMLWriter_INCLUDED
#include "Poco/XML/XML.h"
#include "Poco/SAX/ContentHandler.h"
#include "Poco/SAX/LexicalHandler.h"
#include "Poco/SAX/DTDHandler.h"
#include "Poco/SAX/NamespaceSupport.h"
#include "Poco/XML/XMLString.h"
#include "Poco/XML/XMLStream.h"
#include "Poco/XML/Name.h"
#include "Poco/TextEncoding.h"
#include "Poco/StreamConverter.h"
#include <vector>
#include <map>
namespace Poco {
namespace XML {
class Locator;
class XML_API XMLWriter: public ContentHandler, public LexicalHandler, public DTDHandler
/// This class serializes SAX2 ContentHandler, LexicalHandler and
/// DTDHandler events back into a stream.
///
/// Various consistency checks are performed on the written data
/// (i.e. there must be exactly one root element and every startElement()
/// must have a matching endElement()).
///
/// The XMLWriter supports optional pretty-printing of the serialized XML.
/// Note, however, that pretty-printing XML data alters the
/// information set of the document being written, since in
/// XML all whitespace is potentially relevant to an application.
///
/// The writer contains extensive support for XML Namespaces, so that a client
/// application does not have to keep track of prefixes and supply xmlns attributes.
///
/// If the client does not provide namespace prefixes (either by specifying them
/// as part of the qualified name given to startElement(), or by calling
/// startPrefixMapping()), the XMLWriter automatically generates namespace
/// prefixes in the form ns1, ns2, etc.
{
public:
enum Options
{
CANONICAL = 0x00,
/// Do not write an XML declaration (default).
CANONICAL_XML = 0x01,
/// Enables basic support for Canonical XML:
/// - do not write an XML declaration
/// - do not use special empty element syntax
/// - set the New Line character to NEWLINE_LF
/// - write namespace declarations and attributes
/// in canonical order
/// - use default namespace as much as possible
WRITE_XML_DECLARATION = 0x02,
/// Write an XML declaration.
PRETTY_PRINT = 0x04,
/// Pretty-print XML markup.
PRETTY_PRINT_ATTRIBUTES = 0x08
/// Write each attribute on a separate line.
/// PRETTY_PRINT must be specified as well.
};
XMLWriter(XMLByteOutputStream& str, int options);
/// Creates the XMLWriter and sets the specified options.
///
/// The resulting stream will be UTF-8 encoded.
XMLWriter(XMLByteOutputStream& str, int options, const std::string& encodingName, Poco::TextEncoding& textEncoding);
/// Creates the XMLWriter and sets the specified options.
///
/// The encoding is reflected in the XML declaration.
/// The caller is responsible for that the given encodingName matches with
/// the given textEncoding.
XMLWriter(XMLByteOutputStream& str, int options, const std::string& encodingName, Poco::TextEncoding* pTextEncoding);
/// Creates the XMLWriter and sets the specified options.
///
/// The encoding is reflected in the XML declaration.
/// The caller is responsible for that the given encodingName matches with
/// the given textEncoding.
/// If pTextEncoding is null, the given encodingName is ignored and the
/// default UTF-8 encoding is used.
~XMLWriter();
/// Destroys the XMLWriter.
void setNewLine(const std::string& newLineCharacters);
/// Sets the line ending for the resulting XML file.
///
/// Possible values are:
/// * NEWLINE_DEFAULT (whatever is appropriate for the current platform)
/// * NEWLINE_CRLF (Windows),
/// * NEWLINE_LF (Unix),
/// * NEWLINE_CR (Macintosh)
const std::string& getNewLine() const;
/// Returns the line ending currently in use.
void setIndent(const std::string& indent);
/// Sets the string used for one indentation step.
///
/// The default is a single TAB character.
/// The given string should only contain TAB or SPACE
/// characters (e.g., a single TAB character, or
/// two to four SPACE characters).
const std::string& getIndent() const;
/// Returns the string used for one indentation step.
// ContentHandler
void setDocumentLocator(const Locator* loc);
/// Currently unused.
void startDocument();
/// Writes a generic XML declaration to the stream.
/// If a document type has been set (see SetDocumentType),
/// a DOCTYPE declaration is also written.
void endDocument();
/// Checks that all elements are closed and prints a final newline.
void startFragment();
/// Use this instead of StartDocument() if you want to write
/// a fragment rather than a document (no XML declaration and
/// more than one "root" element allowed).
void endFragment();
/// Checks that all elements are closed and prints a final newline.
void startElement(const XMLString& namespaceURI, const XMLString& localName, const XMLString& qname, const Attributes& attributes);
/// Writes an XML start element tag.
///
/// Namespaces are handled as follows.
/// 1. If a qname, but no namespaceURI and localName are given, the qname is taken as element name.
/// 2. If a namespaceURI and a localName, but no qname is given, and the given namespaceURI has been
/// declared earlier, the namespace prefix for the given namespaceURI together with the localName
/// is taken as element name. If the namespace has not been declared, a prefix in the form
/// "ns1", "ns2", etc. is generated and the namespace is declared with the generated prefix.
/// 3. If all three are given, and the namespace given in namespaceURI has not been declared, it is declared now.
/// Otherwise, see 2.
void startElement(const XMLString& namespaceURI, const XMLString& localName, const XMLString& qname);
/// Writes an XML start element tag with no attributes.
/// See the other startElement() method for more information.
void endElement(const XMLString& namespaceURI, const XMLString& localName, const XMLString& qname);
/// Writes an XML end element tag.
///
/// Throws an exception if the name of doesn't match the
/// one of the most recent startElement().
void emptyElement(const XMLString& namespaceURI, const XMLString& localName, const XMLString& qname);
/// Writes an empty XML element tag (<elem/>).
void emptyElement(const XMLString& namespaceURI, const XMLString& localName, const XMLString& qname, const Attributes& attributes);
/// Writes an empty XML element tag with the given attributes (<elem attr1="value1"... />).
void characters(const XMLChar ch[], int start, int length);
/// Writes XML character data. Quotes, ampersand's, less-than and
/// greater-than signs are escaped, unless a CDATA section
/// has been opened by calling startCDATA().
///
/// The characters must be encoded in UTF-8 (if XMLChar is char) or
/// UTF-16 (if XMLChar is wchar_t).
void characters(const XMLString& str);
/// Writes XML character data. Quotes, ampersand's, less-than and
/// greater-than signs are escaped, unless a CDATA section
/// has been opened by calling startCDATA().
///
/// The characters must be encoded in UTF-8 (if XMLChar is char) or
/// UTF-16 (if XMLChar is wchar_t).
void rawCharacters(const XMLString& str);
/// Writes the characters in the given string as they are.
/// The caller is responsible for escaping characters as
/// necessary to produce valid XML.
///
/// The characters must be encoded in UTF-8 (if XMLChar is char) or
/// UTF-16 (if XMLChar is wchar_t).
void ignorableWhitespace(const XMLChar ch[], int start, int length);
/// Writes whitespace characters by simply passing them to
/// characters().
void processingInstruction(const XMLString& target, const XMLString& data);
/// Writes a processing instruction.
void startPrefixMapping(const XMLString& prefix, const XMLString& namespaceURI);
/// Begin the scope of a prefix-URI Namespace mapping.
/// A namespace declaration is written with the next element.
void endPrefixMapping(const XMLString& prefix);
/// End the scope of a prefix-URI mapping.
void skippedEntity(const XMLString& name);
/// Does nothing.
void dataElement(const XMLString& namespaceURI, const XMLString& localName, const XMLString& qname, const XMLString& data,
const XMLString& attr1 = XMLString(), const XMLString& value1 = XMLString(),
const XMLString& attr2 = XMLString(), const XMLString& value2 = XMLString(),
const XMLString& attr3 = XMLString(), const XMLString& value3 = XMLString());
/// Writes a data element in the form <name attr1="value1"...>data</name>.
// LexicalHandler
void startCDATA();
/// Writes the <![CDATA[ string that begins a CDATA section.
/// Use characters() to write the actual character data.
void endCDATA();
/// Writes the ]]> string that ends a CDATA section.
void comment(const XMLChar ch[], int start, int length);
/// Writes a comment.
void startDTD(const XMLString& name, const XMLString& publicId, const XMLString& systemId);
/// Writes a DTD declaration.
void endDTD();
/// Writes the closing characters of a DTD declaration.
void startEntity(const XMLString& name);
/// Does nothing.
void endEntity(const XMLString& name);
/// Does nothing.
// DTDHandler
void notationDecl(const XMLString& name, const XMLString* publicId, const XMLString* systemId);
void unparsedEntityDecl(const XMLString& name, const XMLString* publicId, const XMLString& systemId, const XMLString& notationName);
static const std::string NEWLINE_DEFAULT;
static const std::string NEWLINE_CR;
static const std::string NEWLINE_CRLF;
static const std::string NEWLINE_LF;
// Namespace support.
XMLString uniquePrefix();
/// Creates and returns a unique namespace prefix that
/// can be used with startPrefixMapping().
bool isNamespaceMapped(const XMLString& namespc) const;
/// Returns true if the given namespace has been mapped
/// to a prefix in the current element or its ancestors.
// Misc.
int depth() const;
/// Return the number of nested XML elements.
///
/// Will be -1 if no document or fragment has been started,
/// 0 if the document or fragment has been started,
/// 1 if the document element has been written and
/// > 1 for every element nested within the document element.
protected:
typedef std::map<XMLString, XMLString> AttributeMap;
typedef std::map<XMLString, std::pair<XMLString, XMLString>> CanonicalAttributeMap;
void writeStartElement(const XMLString& namespaceURI, const XMLString& localName, const XMLString& qname, const Attributes& attributes);
void writeCanonicalStartElement(const XMLString& namespaceURI, const XMLString& localName, const XMLString& qname, const Attributes& attributes);
void writeEndElement(const XMLString& namespaceURI, const XMLString& localName, const XMLString& qname);
void writeMarkup(const std::string& str) const;
void writeXML(const XMLString& str) const;
void writeXML(XMLChar ch) const;
void writeNewLine() const;
void writeIndent() const;
void writeIndent(int indent) const;
void writeName(const XMLString& prefix, const XMLString& localName);
void writeXMLDeclaration();
void closeStartTag();
void declareNamespaces(const XMLString& namespaceURI, const XMLString& localName, const XMLString& qname, const Attributes& attributes);
void declareAttributeNamespaces(const Attributes& attributes);
void addNamespaceAttributes(AttributeMap& attributeMap);
void addNamespaceAttributes(CanonicalAttributeMap& attributeMap);
void addAttributes(AttributeMap& attributeMap, const Attributes& attributes, const XMLString& elementNamespaceURI);
void addAttributes(CanonicalAttributeMap& attributeMap, const Attributes& attributes, const XMLString& elementNamespaceURI);
void writeAttributes(const AttributeMap& attributeMap);
void writeAttributes(const CanonicalAttributeMap& attributeMap);
void prettyPrint() const;
static std::string nameToString(const XMLString& localName, const XMLString& qname);
private:
struct Namespace
{
Namespace(const XMLString& thePrefix, const XMLString& theNamespaceURI):
prefix(thePrefix),
namespaceURI(theNamespaceURI)
{
}
XMLString prefix;
XMLString namespaceURI;
};
typedef std::vector<Name> ElementStack;
Poco::OutputStreamConverter* _pTextConverter;
Poco::TextEncoding* _pInEncoding;
Poco::TextEncoding* _pOutEncoding;
int _options;
std::string _encoding;
std::string _newLine;
int _depth;
int _elementCount;
bool _inFragment;
bool _inCDATA;
bool _inDTD;
bool _inInternalDTD;
bool _contentWritten;
bool _unclosedStartTag;
ElementStack _elementStack;
NamespaceSupport _namespaces;
int _prefix;
bool _nsContextPushed;
std::string _indent;
static const std::string MARKUP_QUOTENC;
static const std::string MARKUP_AMPENC;
static const std::string MARKUP_LTENC;
static const std::string MARKUP_GTENC;
static const std::string MARKUP_TABENC;
static const std::string MARKUP_CRENC;
static const std::string MARKUP_LFENC;
static const std::string MARKUP_LT;
static const std::string MARKUP_GT;
static const std::string MARKUP_SLASHGT;
static const std::string MARKUP_LTSLASH;
static const std::string MARKUP_COLON;
static const std::string MARKUP_EQQUOT;
static const std::string MARKUP_QUOT;
static const std::string MARKUP_SPACE;
static const std::string MARKUP_TAB;
static const std::string MARKUP_BEGIN_CDATA;
static const std::string MARKUP_END_CDATA;
};
//
// inlines
//
inline int XMLWriter::depth() const
{
return _depth;
}
} } // namespace Poco::XML
#endif // XML_XMLWriter_INCLUDED